tyvek???

[mwilliamshs]

no to spray foam for me because:

1. it doesn't adhere to the steel it just fills gaps so with age, vibration, hot, cold, etc it can become loose in the cavity and make noise. squeak, thud, crunch...no thanks

2. it will trap moisture and that's what we DON'T want, trapped moisture. it's a vapor barrier.

3. it is a solid dissolved in a liquid which evaporates in curing. whatever this liquid is that's capable of dissolving the solids can very well dissolve the metal in your van, the paint on its interior surface, or even just etch your steel van body. bare steel, condensation...rust. to say nothing of how this stuff can affect plastics, rubber door gaskets, wiring (it'll dissolve some wire insulators).

4. if the wrong expansion rates are used or some unforeseen circumstances arise, your sheetmetal will be deformed by its expansion. I've seen this BUST and I mean like a torpedo through the hull, an aluminum boat when the proper foam was installed at a very reputable boat-builder but was shot into an aluminum hull that had been heated by the sun, unbeknownst to the foam installer.

5. it's a pain to hack through the foam for future service/repairs.

[REF]

Yes, I've spent some time running wires, and having others run wires, re run wires and add stuff like sat antennas, cb antennas, speaker wire and other cables through cavities in the van and other cars, it's the only way to run that stuff and where a lot of the factory wiring is run, you'd have a real hard time getting it through all that foam if you fill the cavities. I've seen low expansion foam sprayed on the interior walls prior to buildout, not sure if that van was getting cabs or carpet liner, might be a little lumpy to get everything to fit just right.
Not sure if the link was posted, there was an interior build that someone did that addressed all this.

Edit: here it is, long post but good info
viewtopic.php?t=11990

[FastAl]

What about some sort of Rhino Liner or other.

[mwilliamshs]

Originally Posted by FastAl

What about some sort of Rhino Liner or other.

I think it's a good idea to put a continuous layer of a thick protective sort on interior surfaces for the purposes of insulation, surface and seam sealing, and sound control. I plan to use DIY lizardskin, which is made from ceramic microspheres and paint. Lots of info online about this. The bedliner type stuff would be nice if maybe a little heavy and in my experience is both rougher than I'd like underfoot in a camper (unless it'd be carpeted over I guess) and very heavy. Only the commercially applied heated and vulcanized materials seem to last. The spray or roll-on DIY stuff is always too soft to me. It tears and scrapes off easily. I've used several kinds.

LONG STORY ABOUT DIY BEDLINER FAILING:

The most illustrative example of the differences in commercial and DIY was when I had a commercial liner in a work truck that hauled steel weights day-in and day-out. The commercially applied vulcanized bedliner, Rhino brand, held up great for 8 years or so but did have places worn through in the "valleys" of where the weights would tip on edge and lay in them. There was no rust because the metal was kept bare from daily use. We unloaded the bed, blew it out with an air gun, hand washed it with dish soap, rinsed, scrubbed around the worn areas with scotch-brite pads, washed and rinsed again, sprayed and wiped with prep-spray, used a quality etching primer in accordance with its label, followed by auto-body quality paint following its instructions, scuffed it for adhesion, followed by a diy spray-on bedliner product, name-brand forgotten but it was "the best" at the time and i think it had kevlar in it and was applied in accordance with its instructions. This was over the course of about 2 weeks when the was not used and was parked inside. We had the vinyl wrap on the truck replaced and put new seats in at the time. After 8 years over 250k miles in forrests, mines, mills, and pits it was due lol. The DIY bedliner looked good 2 weeks or so after application and blended very well in the "patched" areas when the truck was returned to service. After less than a month of use it was all gone. It had worn through, peeled off, and disappeared. I don't know of anything that could have been done better in the process. I really don't. Most DIY'ers aren't this careful or methodical in their applications and while I've read of people being more successful in their uses of DIY bedliner, I'm unconvinced and won't waste my time, $, or energy on it again.

BACK TO VANS:

So I do think the idea of coating the inside of vans is smart and I plan to, but I don't want to spend several hundred dollars on it (truck beds in my area are normally over $700 at line-x or rhino and I can expect a van just as long but with tall walls to be more $) and I don't want the weight of bedliner anyway, So I'll go with the DIY lizardskin for better insulation properties, less $, and less weight.